Recent results from CLEOII: charm physics

In the last decade the CLEO II collaboration, using the CESR e(+)e(-) storage ring, has accumulated nearly 15fb(-1) of luminosity. in the energy region around 10.5 GeV, corresponding to the production of more than 3.10(7) charmed particles (apart from daughters of B meson decay). This has produced new results in the spectroscopy of charmed baryons and mesons and a much improved limit on D-0 - <(D-0)over bar> mixing. We present evidence for an excitation of the Xi(c), seen in both charge states; namely, the Xi(c)', the J(p) = 1/2(+) c{sq} state, which is symmetric under exchange of light quark quantum numbers. Another state is seen in the decays to Xi(c)(+)pi(+)pi(-) and Xi(c)(0)pi(+)pi(-) via an Intermediate Xi(c)*, and Is consistent with the Xi(c1), the J(p) = 3/2(-) p-wave state analogous to the Lambda(c1)(+)(2625). The mass differences relative to the ground state are: M(Xi(c)(+)') - M(Xi(c)) = (107.8 +/- 1.7 +/- 2.5) MeV/c(2), M(Xi(c)(0)') - M(Xi(c)) = (107.0 +/- 1.5 +/- 2.5) MeV/c(2), M(Xi(c1)(+)) - M(Xi(c)(+)) = (348.6 +/- 0.6 +/- 1.0) MeV/c(2), and M(Xi(c1)(0)) - M(Xi(c)(0)) = (347.2 +/- 0.7 +/- 2.0) MeV/c(2). We have made the first (preliminary) measurements of the natural widths of the Sigma(c)(++) and Sigma(c)(0) baryons: Gamma(++) = (2.98(-.35)(+.38) +/- 0.5) MeV, and Gamma(0) = (2.63(-.33)(+.36) +/- 0.5) MeV. In the charmed meson sector we find evidence for a wide 1(+) state, the D-1(0)(2460). Its mass is (2.461(-.034)(+.041) +/- .010 +/- .032) GeV; its width is (290(-74)(+101) +/- 26 +/- 36) MeV. We find no supporting evidence for the D*'(+), a purported radial excitation claimed by the Delphi group at a mass of (2637 +/- 2 +/- 6) MeV. Finally we are able, using "wrong-sign" (DCSD) K pi decays to make the following measurements: 1) the observed ratio of DCSD decays relative to the Cabibbo-allowed rate is R-ws = (0.34 +/- 0.7 +/- .06)%, 2) the mixing parameters are bounded, at 95% confidence, by x'(2) <. 001 and -.059 < y' < .003. x' and y' are, in the absence of final state phase differences, the real and imaginary parts of delta M/Gamma.